DEHYDRATED CULTURE MEDIA 29 



MEDIA FOR THE EXAMINATION 

 OF WATER AND SEWAGE 



The dehydrated culture media listed in this section conform to the formulae 

 given in "Standard Methods for the Examination of Water and Sewage," Ninth 

 Edition, 1946, of the American Public Health Association and the American 

 Water Works Association. Carefully selected standardized ingredients are used in 

 the exact proportions specified in the "Standard Methods" formulae. The reac- 

 tion of each medium is carefully adjusted so that the final reaction will fall 

 within the range of pH recommended in "Standard Methods." 



The American Public Health Association has permitted the use of dehydrated 

 media of "Standard Methods" composition continuously since 1923 in every 

 edition of its "Standard Methods for the Examination of Water and Sewage," 

 including the current Ninth Edition. 



The U. S. Public Health Service Drinking Water Standards^ specify that the 

 procedures recommended in "Standard Methods of Water Analysis" of the Amer- 

 ican Public Health Association be followed in all details, including the culture 

 media. It is, therefore, permissible for Bacto Dehydrated Culture Media to be 

 used in the testing of the potability of water according to the U. S. Public Health 

 Service Drinking Water Standards. 



A guide for the selection of culture media listed in this section is given on 



page 25. 



1 Public Health Reports, 61:376:1946 

 (Reprint No. 2697). 



"STANDARD METHODS" MEDIA 



The media listed in this section are used for the bacteriological examination of 

 water in accordance with the procedures of "Standard Methods for the Examina- 

 tion of Water and Sewage." 



BACTO 



NUTRIENT BROTH (B3) 



DEHYDRATED 



Bacto-Beef Extract 3 g. 



Bacto-Peptone 5 g. 



Bacto-Nutrient Broth is a peptone meat extract liquid medium recommended 

 for general laboratory use for the cultivation of the microorganisms that are not 

 exacting in food requirements. Bacto-Nutrient Broth is prepared in accordance 

 v/ith the formula specified by the American Public Health Association and Amer- 

 ican Water Works Association's "Standard Methods for the Examination of Water 

 and Sewage"^ and "Standard Methods for the Examination of Dairy Products"^ 

 this medium has been prepared to give to bacteriologists an Extract Broth of 

 approved and standard formula. It is also recommended as a base to which a 



